Nantucket Signals shows longer blue tails. N635 is assigned to the 1845 and 1849 sailings and also occurs in the painting; N634 is undated.
Navigator operated from Nantucket in 1841–1862 and was then sold to Boston. Owners are unknown for the recorded voyages, with Mathew Crosby as agent.
Keep the explicit scope label independent; no alias or company identity is inferred.